Preimplantation Genetic Testing (PGT)

What is preimplantation genetic testing?

A global increase in demand for vitro fertilization (IVF) over the last 30 years has driven the development and adoption of preimplantation genetic testing services. Preimplantation genetic testing (PGT) is a procedure that can be performed as part of an in vitro fertilization (IVF) cycle. PGT is used to detect chromosomal abnormalities in embryos, which are potential causes of implantation failure, miscarriage and in utero death. It allows reproduction specialists to determine the viability of embryos before they are transferred into a woman’s uterus.

PGT can also be used to test for specific gene mutations in an embryo, including those associated with inherited genetic diseases or conditions. PGT is most often chosen by couples who have previously had multiple miscarriages or at least one child affected by a serious genetic disorder. A doctor may also recommend PGT if the woman has had several unsuccessful IVF cycles where few or no viable embryos resulted. PGT is an option for IVF patients who want to decrease the chances of having a child with a genetic disorder.

How is preimplantation genetic testing performed?

PGT is a remarkable, non-invasive test that measures the genetic make-up of embryos before they are implanted in an IVF cycle. Preimplantation genetic testing is an in vitro fertilization procedure that helps detect specific genetic diseases in embryos prior to being placed in the uterus. Capturing the family history is an important first step in PGT to identify risk factors for possible inherited diseases and may inform the diseases that are tested for. Capturing the family history also allows genetic counsellors to explore the concerns of IVT patients based on their family history.

The embryos are tested at least once by their fourth cell division. Their DNA is sequenced and compared with the mother’s DNA and father’s DNA to help predict the range of diseases they might develop in life. The purpose of the procedure is to identify embryos that do not contain any genetic mutations.

This powerful tool allows for the genetic screening of early stage embryos. By identifying and selectively transferring an unaffected embryo, and therefore not transferring any affected embryos to the uterus, families are able to avoid genetic disease in their offspring.

Some genetic conditions that can be tested for with preimplantation genetic testing include Cystic Fibrosis, Sickle Cell Anemia, and Fragile X syndrome.

How can patients benefit from preimplantation genetic testing?

Preimplantation genetic testing (PGT) can ensure that you and your partner don’t pass on any genetic diseases to your baby. It is risky to have children if either partner has a family history of genetic diseases. Preimplantation genetic testing can ensure that you and your partner don’t pass on any genetic diseases to your baby.

Cells are taken from embryos prior to being frozen; these cells are then tested for genetic abnormalities that are linked with inherited diseases. The results of these tests will inform a patient’s decision about whether to keep those embryos and / or have them implanted.

While there are many things to consider, including the genes you pass onto your baby, genetic testing can make sure that your baby is healthy. The decision to undertake preimplantation genetic testing and consideration of the results is best supported by a genetic counsellor who can ensure IVT patients have fully consider a range of possible implications for undertaking the test and learning of the results.

Key Takeaways

  • Preimplantation genetic testing, or PGT, is an effective way to test for genetic diseases and chromosomal abnormalities.
  • Inherited diseases such as Cystic Fibrosis, Sickle Cell Anemia, and Fragile X syndrome can be detected before implanting embryos.
  • IVF patients can avoid passing on detectable inherited diseases to their off spring.